Polymerization catalyst compositions and processes to produce polymers and bimodal polymers

ABSTRACT

A process to produce a first catalyst composition is provided. The process comprises contacting at least one first organometal compound and at least one activator to produce the first catalyst composition. The activator is selected from the group consisting of aluminoxanes, fluoro-organo borates, and treated solid oxide components in combination with at least one organoaluminum compound. In another embodiment of this invention, a process to produce a second catalyst composition for producing bimodal polymers is provided. The process comprises contacting at least one first organometal compound, at least one activator, and at least one second organometal compound to produce the second catalyst composition. The first and second catalyst compositions are also provided as well as polymerization processes using these compositions to produce polymers.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 09/561,306 filed Apr. 28, 2000, now U.S. Pat. No. 6,528,448.

FIELD OF THE INVENTION

This invention is related to the field of polymerization catalystcompositions.

BACKGROUND OF THE INVENTION

Zirconium based metallocene polymerization catalysts, such as,bis(cyclopentadienyl)zirconium dichloride, are well known and arecommonly used as ethylene polymerization catalysts when combined withactivators, such as, for example, methylaluminoxane (MAO). A descriptionof such catalysts can be found, for example, in Angew. Chem. 88, 689,1976, Justus Liebigs Ann. Chem. 1975, 463, and U.S. Pat. No. 5,324,800,herein incorporated by reference. Zirconium based metallocenes can bequite active, but unfortunately, these metallocenes also produce afairly narrow molecular weight distribution.

For many extrusion grade applications, such as film, pipe, and blowmolding, polymers having broad molecular weight distributions arepreferred. Especially preferred are so-called “bimodal distribution”polymers because of the superior toughness imparted to the finalmanufactured resin part. See, for example, U.S. Pat. Nos. 5,306,775 and5,319,029, herein incorporated by reference. The superior toughness canresult from concentrating the short chain branching in the highmolecular weight portion of the molecular weight distribution. Extremelylong and highly branched chains can be more effective as tie moleculesbetween the crystalline phases. These tie molecules can impart higherimpact resistance and environmental stress crack resistance to bimodalpolymers.

To produce such bimodal polymers from metallocene catalysts, it isnecessary to combine two metallocenes. A first metallocene is utilizedto produce a low molecular weight polymer having little branching.Zirconium based metallocenes can function well in such a role. A secondmetallocene is utilized to produce the high molecular weight polymer,and this second metallocene should also simultaneously incorporatecomonomers, such as hexene, very well. In this way, the longest chainscontain the most branching, which is ideal for the production of bimodalpolymers.

Unfortunately, the requirements of the second metallocene has beendifficult to fill. Of the zirconium based metallocenes describedpreviously, few generate very high molecular weight polymer. Of thesefew, activity or stability is often poor, and comonomer incorporation isnot impressive. A second class of metallocene catalysts, calledhalf-sandwich titanium based metallocenes, do produce very highmolecular weight polymer, and some even incorporate hexene well. SeeOrganometallics, 1966, 15, 693-703 and Macromolecules 1998, 31,7588-7597. Half-sandwich titanium based metallocenes have a titaniumbonded to one cyclopentadienyl, indenyl, or fluorenyl group. However,these compounds are not noted for their high activity.

There is a need in the polymer industry for a metallocene catalyst ororganometal catalyst that produces high molecular weight polymer, has ahigh activity, and incorporates comonomers efficiently that can be usedalone or in combination with other metallocenes.

It is an object of this invention to provide a first organometalcompound capable of producing high molecular weight polymers.

It is another object of this invention to provide a process forproducing a first catalyst composition. The process comprises contactingat least one first organometal compound and at least one activator.

It is another object of this invention to provide the first catalystcomposition.

It is another object of this invention to provide a polymerizationprocess. The process comprises contacting the first catalyst compositionwith one or more alpha olefins in a polymerization zone underpolymerization conditions to produce a high molecular weight polymer.

It is another object of this invention to provide the high molecularweight polymer.

It is another object of this invention to provide a process forproducing a second catalyst composition capable of producing bimodalpolymers. The process comprises contacting the first organometalcompound, at least one activator, and at least one second organometalcompound.

It is another object of this invention to provide the second catalystcomposition capable of producing bimodal polymers.

It is a further object of this invention to provide a process for theproduction of bimodal polymers. The process comprises contacting thesecond catalyst composition with one or more alpha olefins in apolymerization zone under polymerization conditions to produce thebimodal polymers.

It is yet a further object of this invention to provide the bimodalpolymer.

SUMMARY OF THE INVENTION

According to one embodiment of this invention, a process to produce afirst catalyst composition is provided. The process comprises contactingat least one first organometal compound and at least one activator toproduce the first catalyst composition;

wherein the first organometal compound is represented by the formulaR₂CpM¹—O—M²CpR₂

wherein M¹ is selected from the group consisting of titanium, zirconium,and hafnium;

wherein M² is selected from the group consisting of a transition metal,a lanthamide metal, an actinide metal, a Group IIIB metal, a Group IVBmetal, a Group VB metal, and a Group VIB metal;

wherein Cp is independently selected from the group consisting ofcyclopentadienyls, indenyls, fluorenyls, substituted cyclopentadienyls,substituted indenyls, and substituted fluorenyls;

wherein substituents on the substituted cyclopentadienyls, substitutedindenyls, and substituted fluorenyls of Cp are selected from the groupconsisting of aliphatic groups, cyclic groups, combinations of aliphaticand cyclic groups, silyl groups, alkyl halide groups, halides,organometallic groups, phosphorus groups, nitrogen groups, silicon,phosphorus, boron, germanium, and hydrogen;

wherein R is independently selected from the group consisting ofhalides, aliphatic groups, substituted aliphatic groups, cyclic groups,substituted cyclic groups, combinations of aliphatic groups and cyclicgroups, combinations of substituted aliphatic groups and cyclic groups,combinations of aliphatic groups and substituted cyclic groups,combinations of substituted aliphatic groups and substituted cyclicgroups, amido groups, substituted amido groups, phosphido groups,substituted phosphido groups, alkyloxide groups, substituted alkyloxidegroups, aryloxide groups, substituted aryloxide groups, organometallicgroups, and substituted organometallic groups; and

wherein the activator is selected from the group consisting ofaluminoxanes, fluoro-organo borates, and treated solid oxide componentsin combination with at least one organoaluminum compound.

In another embodiment of this invention, a process to produce a secondcatalyst composition for producing bimodal polymers is provided. Theprocess comprises contacting at least one first organometal compound, atleast one activator, and at least one second organometal compound toproduce the second catalyst composition;

wherein the second organometal compound is represented by the formula,(C₅R₅)₂ZrX₂;

wherein the R is the same or different and is independently selectedfrom the group consisting of hydrogen and a hydrocarbyl group havingfrom 1 to about 10 carbon atoms;

wherein the hydrocarbyl group is selected from the group consisting of alinear or branched alkyl, a substituted or unsubstituted aryl, and analkylaryl; and

wherein X is the same or different and is independently selected fromthe group consisting of a halide, an alkyl, an alkylaryl having from 1to about 10 carbon atoms, and a triflate.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a graph showing the polymer molecular weight distribution(MWD). The normalized weight fraction per increment of log M [dW/d(logM)] is plotted as a function of the molecular weight (M) in grams permole (g/mol), plotted on a logarithmic (log) scale.

DETAILED DESCRIPTION OF THE INVENTION

In a first embodiment of this invention, a process to produce a firstcatalyst composition is provided. The process comprises contacting atleast one first organometal compound and at least one activator. Thefirst organometal compound is represented by the formula:R₂CpM¹—O—M²CpR₂In this formula, M¹ is selected from the group consisting of titanium,zirconium, and hafnium. Currently, it is preferred when M¹ is titanium.M² is selected from the group consisting of a transition metal, alanthamide, an actinide, a Group IIIB metal, a Group IVB metal, a GroupVB metal, and a Group VIB metal. Preferably, M² is titanium.

In this formula, Cp is independently selected from the group consistingof cyclopentadienyls, indenyls, fluorenyls, substitutedcyclopentadienyls, substituted indenyls, such as, for exampletetrahydroindenyls, and substituted fluorenyls, such as, for example,octahydrofluorenyls.

Substituents on the substituted cyclopentadienyls, substituted indenyls,and substituted fluorenyls of Cp are selected from the group consistingof aliphatic groups, cyclic groups, combinations of aliphatic and cyclicgroups, silyl groups, alkyl halide groups, halides, organometallicgroups, phosphorus groups, nitrogen groups, silicon, phosphorus, boron,germanium, and hydrogen, as long as these groups do not substantially,and adversely, affect the polymerization activity of the firstorganometal compound.

Suitable examples of aliphatic groups are hydrocarbyls, such as, forexample, paraffins and olefins. Suitable examples of cyclic groups arecycloparaffins, cycloolefins, cycloacetylenes, and arenes. Substitutedsilyl groups include, but are not limited to, alkylsilyl groups whereeach alkyl group contains from 1 to about 12 carbon atoms, arylsilylgroups, and arylalkylsilyl groups. Suitable alkyl halide groups havealkyl groups with 1 to about 12 carbon atoms. Suitable organometallicgroups include, but are not limited to, substituted silyl derivatives,substituted tin groups, substituted germanium groups, and substitutedboron groups.

Suitable examples of such substituents are methyl, ethyl, propyl, butyl,tert-butyl, isobutyl, amyl, isoamyl, hexyl, cyclohexyl, heptyl, octyl,nonyl, decyl, dodecyl, 2-ethylhexyl, pentenyl, butenyl, phenyl, chloro,bromo, iodo, trimethylsilyl, and phenyloctylsilyl.

In this formula, R is independently selected from the group consistingof halides, aliphatic groups, substituted aliphatic groups, cyclicgroups, substituted cyclic groups, combinations of aliphatic groups andcyclic groups, combinations of substituted aliphatic groups and cyclicgroups, combinations of aliphatic groups and substituted cyclic groups,combinations of substituted aliphatic groups and substituted cyclicgroups, amido groups, substituted amido groups, phosphido groups,substituted phosphido groups, alkyloxide groups, substituted alkyloxidegroups, aryloxide groups, substituted aryloxide groups, organometallicgroups, and substituted organometallic groups.

Preferably, the first organometal compound can be represented by thefollowing formula:(C₅R₅)TiX₂—O—(C₅R₅)TiX₂In this formula, each R is the same or different and is independentlyselected from the group consisting of hydrogen and a hydrocarbyl grouphaving from 1 to about 10 carbon atoms. The hydrocarbyl group isselected from the group consisting of a linear or branched alkyl, asubstituted or unsubstituted aryl, and an alkylaryl. X is the same ordifferent and is independently selected from the group consisting of ahalide, an alkyl, an alkylaryl having from 1 to about 10 carbon atoms,and a triflate. Suitable first organometal compounds include, forexample, [(C₅H₄CH₃)TiCl₂]₂O, [(C₅H₄CH₂C₆H₅)TiF₂]₂O,[(C₅H₃CH₃C₂H₅)TiBr₂]O, and [(C₅H₅)TiCl₂]₂O. Most preferably, the firstorganometal compound is [(C₅H₅)TiCl₂]₂O. Combinations of these firstorganometal compounds also can be used.

The activator is selected from the group consisting of aluminoxanes,fluoro-organo borates, and at least one treated solid oxide component incombination with at least one organoaluminum compound.

Aluminoxanes, also referred to as poly(hydrocarbyl aluminum oxides), arewell known in the art and are generally prepared by reacting anhydrocarbylaluminum compound with water. Such preparation techniques aredisclosed in U.S. Pat. Nos. 3,242,099 and 4,808,561, the entiredisclosures of which are herein incorporated by reference. The currentlypreferred aluminoxanes are prepared from trimethylaluminum ortriethylaluminum and are sometimes referred to as poly(methyl aluminumoxide) and poly(ethyl aluminum oxide), respectively. It is also withinthe scope of the invention to use an aluminoxane in combination with atrialkylaluminum, such as disclosed in U.S. Pat. No. 4,794,096, thedisclosure of which is herein incorporated by reference.

Generally, any amount of the aluminoxane capable of activating the firstorganometal compound is utilized in this invention. Preferably, themolar ratio of the aluminum in the aluminoxane to the transition metalin the metallocene is in a range of about 1:1 to about 100,000:1, and,most preferably, 5:1 to 15,000:1. Generally, the amount of aluminoxaneadded to a polymerization zone is an amount within a range of about 0.01mg/L to about 1000 mg/L, preferably about 0.1 mg/L to about 100 mg/L.Most preferably, the amount of aluminoxane added is an amount within arange of 1 to 50 mg/L in order to maximize catalyst productivity andactivity.

Fluoro-organo borate compounds also can be used to activate and form thefirst catalyst composition. Any fluoro-organo borate compound known inthe art that is capable of activating an organometal compound can beutilized. Examples of such fluoro-organo borate compounds include, butare not limited to, fluorinated aryl borates, such as,N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,triphenylcarbenium tetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, tris(pentafluorophenyl)boron,N,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate,triphenylcarbenium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, andmixtures thereof. Although not intending to be bound by theory, theseexamples of fluoro-organo borate compounds and related fluoro-organoborates are thought to form “weakly-coordinating” anions when combinedwith organometal compounds as disclosed in U.S. Pat. No. 5,919,983,herein incorporated by reference.

Generally, any amount of fluoro-organo borate compound capable ofactivating the organometal compound is utilized in this invention.Preferably, the amount of the fluoro-organo borate compound is in arange of from about 0.5 mole to about 10 moles of fluoro-organo boratecompound per mole of organometal compound. Most preferably, the amountof the fluoro-organo borate compound is in a range of from 0.8 mole to 5moles of fluoro-organo borate compound per mole of organometal compound.

The aluminoxane and fluoro-organo borate compounds can be supported orunsupported. If supported, generally the support is an inorganic oxide,such as, silica, an aluminate, or combinations thereof. The use of asupported activator can result in a heterogeneous catalyst composition,and an unsupported activator can result in a homogeneous catalystcomposition.

Preferably, the activator is a treated solid oxide component used incombination with an organoaluminum compound. The treated solid oxidecomponent is a halided solid oxide component or a halided,metal-containing solid oxide component. The halided solid oxidecomponent comprises a halogen and a solid oxide component. The halided,metal-containing solid oxide component comprises a halogen, a metal, anda solid oxide component.

The organoaluminum compound can be represented by the following formula:AlR_(3−n)X_(n)

In this formula, R is the same or different and is selected from thegroup consisting of hydride and a hydrocarbyl group having 1 to about 10carbon atoms. The hydrocarbyl group is selected from the groupconsisting of a linear or branched alkyl, a substituted or unsubstitutedaryl and an alkylaryl. X is selected from the group consisting ofhalides and hydrocarbyloxides. The hydrocarbyloxide is selected from thegroup consisting of a linear or branched alkoxide, a substituted orunsubstituted aryloxide and an alkylaryloxide. The number n is either 1or 0. Suitable organoaluminum compounds include, for example,triisobutylaluminum, diethylaluminum hydride, dipentylalumium ethoxide,dipropylaluminum phenoxide, and the mixtures thereof. Preferably, theorganoaluminum compound is trialkylaluminum. Most preferably, it istriisobutylaluminum or triethylaluminum. Combinations of theseorganoaluminum compounds also can be used.

The solid oxide component is prepared from an aluminate selected fromthe group consisting of alumina, silica-alumina, aluminophosphate,aluminoborate, and mixtures thereof. Preferably, the solid oxidecomponent is alumina. The halogen is selected from the group consistingof chlorine and bromine. Preferably, for highest activity, the halogenis chlorine. The metal is selected from the group consisting of zinc,nickel, vanadium, silver, copper, gallium, tin, tungsten, andmolybdenum. Preferably, for high activity and low cost, the metal iszinc.

The solid oxide component has a pore volume greater than about 0.5 cc/g,preferably, greater than about 0.8 cc/g, and most preferably, greaterthan 1.0 cc/g. The solid oxide component has a surface area in a rangeof about 100 to about 1000 m²/g, preferably from about 200 to about 800m²/g, and most preferably, from 250 to 600 m²/g.

To produce the halided solid oxide component, the solid oxide componentis calcined either prior to, during, or after contacting with ahalogen-containing compound. Generally, calcining is conducted for about1 minute to about 100 hours, preferably for about 1 hour to about 50hours, and most preferably, from 3 hours to 20 hours. The calcining isconducted at a temperature in a range of about 200 to about 900° C.,preferably, in a range of about 300 to about 800° C., and mostpreferably, in a range of 400 to 700° C. Any type of suitable ambientcan be used during calcining. Generally, calcining can be completed inan inert atmosphere. Alternatively, an oxidizing atmosphere, such as,for example, oxygen or air, or a reducing atmosphere, such as, forexample, hydrogen or carbon monoxide, can be used.

The halogen-containing compound is at least one compound selected fromthe group consisting of chlorine-containing compounds andbromine-containing compounds. The halogen-containing compound can be ina liquid or preferably, a vapor phase. The solid oxide component can becontacted with the halogen-containing compound by any means known in theart. Preferably, the halogen-containing compound can be vaporized into agas stream used to fluidize the solid oxide component during calcining.The solid oxide component is contacted with the halogen-containingcompound generally from about 1 minute to about 10 hours, preferably,from about 5 minutes to about 2 hours, and most preferably, from 10minutes to 30 minutes. Generally, the solid oxide component is incontact with the halogen-containing compound at a temperature in therange of about 200 to about 900° C., preferably, at a temperature in arange of about 300 to about 800° C., and most preferably, in a range of400 to 700° C. Any type of suitable ambient can be used to contact thesolid oxide component and the halogen-containing compound. Preferably,an inert atmosphere is used. Alternatively, an oxidizing or reducingatmosphere can also be used.

Suitable halogen-containing compounds include volatile or liquid organicchloride or bromide compounds and inorganic chloride or bromidecompounds. Organic chloride or bromide compounds can be selected fromthe group consisting of carbon tetrachloride, chloroform,dichloroethane, hexachlorobenzene, trichloroacetic acid, bromoform,dibromomethane, perbromopropane, and mixtures thereof. Inorganicchloride or bromide compounds can be selected from the group consistingof gaseous hydrogen chloride, silicon tetrachloride, tin tetrachloride,titanium tetrachloride, aluminum trichloride, boron trichloride, thionylchloride, sulfuryl chloride, hydrogen bromide, boron tribromide, silicontetrabromide, and mixtures thereof. Additionally, chlorine and brominegas can be used. Optionally, a fluorine-containing compound or fluorinegas can also be included when contacting the solid oxide component withthe halogen-containing compound to achieve higher activity in somecases.

The amount of halogen present in the halided solid oxide component isgenerally in the range of about 2 to about 150% by weight, preferablyabout 10% to about 100% by weight, and most preferably, 15% to 75% byweight, where the weight percents are based on the weight of the halidedsolid oxide component before calcining or the amount added to aprecalcined solid oxide component.

To produce the halided, metal-containing solid oxide component, thesolid oxide component first is treated with a metal-containing compoundThe metal-containing compound can be added to the solid oxide componentby any method known in the art. In a first method, the metal can beadded to the solid oxide component by cogellation of aqueous materials,as disclosed in U.S. Pat. Nos. 3,887,494; 3,119,569; 4,405,501;4,436,882; 4,436,883; 4,392,990; 4,081,407; 4,981,831; and 4,152,503;the entire disclosures of which are hereby incorporated by reference.

In a second method, the metal-containing compound can be added to thesolid oxide component by cogellation in an organic or anhydrous solutionas disclosed in U.S. Pat. Nos. 4,301,034; 4,547,557; and 4,339,559; theentire disclosures of which are hereby incorporated by reference.

The preferred method is to impregnate the solid oxide component with anaqueous or organic solution of a metal-containing compound prior tocalcining to produce a metal-containing solid oxide component. Asuitable amount of the solution is utilized to provide the desiredconcentration of metal after drying. The metal-containing solid oxidecomponent then is dried by any suitable method known in the art. Forexample, the drying can be accomplished by vacuum drying, spray drying,or flash drying.

Any metal-containing compound known in the art that can impregnate thesolid oxide component with the desired metal can be used in thisinvention. The metal-containing compound can be any water soluble salt,such as, for example, nickel nitrate, zinc chloride, copper sulfate,silver acetate, or vanadyl sulfate. The metal-containing compound canalso be an organometallic compound, such as, for example, nickelacetylacetonate, vanadium ethylhexanoate, zinc naphthenate, and mixturesthereof.

Generally, the amount of metal present is in the range of about 0.1 toabout 10 millimoles per gram of solid oxide component before calcining.Preferably, the amount of metal present is in the range of about 0.5 toabout 5 millimoles per gram of solid oxide component before calcining.Most preferably, the amount of metal present is in the range of 1 to 3millimoles per gram of solid oxide component before calcining.

After the solid oxide component is combined with the metal-containingcompound to produce a metal-containing solid oxide component, it then iscalcined for about 1 minute to about 100 hours, preferably for about 1hour to about 50 hours, and most preferably, from 3 hours to 20 hours.The calcining is conducted at a temperature in a range of about 200 toabout 900° C., preferably, in a range of about 300 to about 800° C., andmost preferably, in a range of 400 to 700° C. Any type of suitableambient can be used during calcining. Generally, calcining can becompleted in an inert atmosphere. Alternatively, an oxidizingatmosphere, such as, for example, oxygen or air, or a reducingatmosphere, such as, for example, hydrogen or carbon monoxide, can beused.

After or during calcining, the metal-containing solid oxide component iscontacted with a halogen-containing compound to produce the halided,metal-containing solid oxide component. Methods for contacting themetal-containing solid oxide component with the halogen-containingcompound are the same as discussed previously for the halided solidoxide component.

Optionally, the metal containing solid oxide component also can betreated with a fluorine-containing compound before, during, or aftercontacting the halogen-containing compound, which can further increasethe activity. Any fluorine-containing compound capable of contacting thesolid oxide component during the calcining step can be used. Organicfluorine-containing compounds of high volatility are especially useful.Such organic fluorine-containing compounds can be selected from thegroup consisting of freons, perfluorohexane, perfluorobenzene,fluoromethane, trifluoroethanol, and mixtures thereof. Gaseous hydrogenfluoride or fluorine itself can be used. One convenient method ofcontacting the solid oxide component is to vaporize afluorine-containing compound into a gas stream used to fluidize thesolid oxide component during calcination.

In a preferred first embodiment, a process to produce a first catalystcomposition is provided. The process comprises contacting,bis(cyclopentadienyl titanium dichloride)oxide, (CpTiCl₂)₂O, achlorided, zinc-containing alumina, and an organoaluminum compoundselected from the group consisting of triisobutyl aluminum andtriethylaluminum to produce the first catalyst composition. The amountof zinc present is in the range of about 0.5 millimoles to about 5millimoles of zinc per gram of alumina. The chloriding treatmentconsists of exposure to a volatile chlorine-containing compound at about500 to about 700° C.

The catalyst compositions of this invention can be produced bycontacting the first organometal compound and the activator together.This contacting can occur in a variety of ways, such as, for example,blending. Furthermore, each of these compounds can be fed into thereactor separately, or various combinations of these compounds can becontacted together before being further contacted in the reactor, or allthree compounds can be contacted together before being introduced intothe reactor.

Currently, one method is to first contact a first organometal compoundand the treated solid oxide component together, for about 1 minute toabout 24 hours, preferably, about 1 minute to about 1 hour, at atemperature from about 10° C. to about 100° C., preferably 15° C. to 50°C., to form a first mixture, and then contact this first mixture with anorganoaluminum compound to form the first catalyst composition.

Another method is to precontact the first organometal compound, theorganoaluminum compound, and the treated solid oxide component beforeinjection into a polymerization reactor for about 1 minute to about 24hours, preferably, 1 minute to 1 hour, at a temperature from about 10°C. to about 200° C., preferably 20° C. to 80° C. to produce the firstcatalyst composition.

A weight ratio of the organoaluminum compound to the treated solid oxidecomponent in the first catalyst composition ranges from about 5:1 toabout 1:1000, preferably, from about 3:1 to about 1:100, and mostpreferably, from 1:1 to 1:50.

A weight ratio of the treated solid oxide component to the firstorganometal compound in the first catalyst composition ranges from about10,000:1 to about 1:1, preferably, from about 1000:1 to about 10:1, andmost preferably, from 250:1 to 20:1. These ratios are based on theamount of the components combined to give the first catalystcomposition.

When the treated solid oxide component is utilized, after contacting thecompounds, the first catalyst composition comprises a post-contactedfirst organometal compound, a post-contacted organoaluminum compound,and a post-contacted treated solid oxide component. It should be notedthat the post-contacted solid oxide component is the majority, byweight, of the first catalyst composition. Often times, specificcomponents of a catalyst are not known, therefore, for this invention,the first catalyst composition is described as comprising post-contactedcompounds.

A weight ratio of the post-contacted organoaluminum compound to thepost-contacted treated solid oxide component in the first catalystcomposition ranges from about 5:1 to about 1:1000, preferably, fromabout 3:1 to about 1:100, and most preferably, from 1:1 to 1:50.

A weight ratio of the post-contacted treated solid oxide component tothe post-contacted first organometal compound in the first catalystcomposition ranges from about 10,000:1 to about 1:1, preferably, fromabout 1000:1 to about 10:1, and most preferably, from 250:1 to 20:1.

When comparing activities, the polymerization runs should occur at thesame polymerization conditions. It is preferred if the activity of thefirst catalyst composition is greater than about 1000 grams of polymerper gram of activator per hour, more preferably greater than about 2000,and most preferably greater than 3000. This activity is measured underslurry polymerization conditions, using isobutane as the diluent, andwith a polymerization temperature of 90° C., and an ethylene pressure of550 psig. The reactor should have substantially no indication of anywall scale, coating or other forms of fouling.

One of the important aspects of this invention is that no aluminoxaneneeds to be used in order to form the first catalyst composition.Aluminoxane is an expensive compound that greatly increases polymerproduction costs. This also means that no water is needed to help formsuch aluminoxanes. This is beneficial because water can sometimes kill apolymerization process. It should be noted that no fluorophenyl borateor other fluoro-organo boron compounds need to be used in order to formthe first catalyst composition. Additionally, no organochromiumcompounds or MgCl₂ need to be added to form the invention. Althoughaluminoxane, fluoro-organo boron compounds, organochromium compounds, orMgCl₂ are not needed in the preferred embodiments, these compounds canbe used in other embodiments of this invention.

In a second embodiment of this invention, a process comprisingcontacting at least one monomer and the first catalyst composition toproduce at least one polymer is provided. The term “polymer” as used inthis disclosure includes homopolymers and copolymers. The first catalystcomposition can be used to polymerize at least one monomer to produce ahomopolymer or a copolymer. Usually, homopolymers are comprised ofmonomer residues, having 2 to about 20 carbon atoms per molecule,preferably 2 to about 10 carbon atoms per molecule. Currently, it ispreferred when at least one monomer is selected from the groupconsisting of ethylene, propylene, 1-butene, 3-methyl-1-butene,1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene,3-ethyl-1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and mixturesthereof.

When a homopolymer is desired, it is most preferred to polymerizeethylene or propylene. When a copolymer is desired, the copolymercomprises monomer residues and one or more comonomer residues, eachhaving from about 2 to about 20 carbon atoms per molecule. Suitablecomonomers include, but are not limited to, aliphatic 1-olefins havingfrom 3 to 20 carbon atoms per molecule, such as, for example, propylene,1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, and otherolefins and conjugated or nonconjugated diolefins such as 1,3-butadiene,isoprene, piperylene, 2,3-dimethyl-1,3-butadiene, 1,4-pentadiene,1,7-hexadiene, and other such diolefins and mixtures thereof. When acopolymer is desired, it is preferred to polymerize ethylene and atleast one comonomer selected from the group consisting of 1-butene,1-pentene, 1-hexene, 1-octene, and 1-decene. The amount of comonomerintroduced into a reactor zone to produce a copolymer is generally fromabout 0.01 to about 10 weight percent comonomer based on the totalweight of the monomer and comonomer, preferably, about 0.01 to about 5,and most preferably, 0.1 to 4. Alternatively, an amount sufficient togive the above described concentrations, by weight, in the copolymerproduced can be used.

Processes that can polymerize at least one monomer to produce a polymerare known in the art, such as, for example, slurry polymerization, gasphase polymerization, and solution polymerization. It is preferred toperform a slurry polymerization in a loop reaction zone. Suitablediluents used in slurry polymerization are well known in the art andinclude hydrocarbons which are liquid under reaction conditions. Theterm “diluent” as used in this disclosure does not necessarily mean aninert material; it is possible that a diluent can contribute topolymerization. Suitable hydrocarbons include, but are not limited to,cyclohexane, isobutane, n-butane, propane, n-pentane, isopentane,neopentane, and n-hexane. Furthermore, it is most preferred to useisobutane as the diluent in a slurry polymerization. Examples of suchtechnology can be found in U.S. Pat. Nos. 4,424,341; 4,501,885;4,613,484; 4,737,280; and 5,597,892; the entire disclosures of which arehereby incorporated by reference.

The first catalyst composition used in this process produce good qualitypolymer particles without substantially fouling the reactor. When thefirst catalyst composition is to be used in a loop reactor zone underslurry polymerization conditions, it is preferred when the particle sizeof the treated solid oxide component is in the range of about 10 toabout 1000 microns, preferably about 25 to about 500 microns, and mostpreferably, 50 to 200 microns, for best control during polymerization.

One novelty of this invention is that butene can be formed duringethylene polymerization. The butene then is copolymerized by theorganometal compound to yield ethylene-butene copolymers even though nobutene is fed to the reactor. Thus, the polymers produced from theinventive catalyst composition can contain up to about 1 weight percentethyl branching even though no butene is fed to the reactor.

In a third embodiment of this invention, a process is provided whereinthe first catalyst composition is further contacted with at least onesecond organometal compound to produce a second catalyst compositioncapable of producing bimodal polymers. The second organometal compoundcan be represented by the following formula:(C₅R₅)₂ZrX₂In this formula, each R is the same or different and is selected fromthe group consisting of hydrogen and a hydrocarbyl group having from 1to about 10 carbon atoms. The hydrocarbyl group is selected from thegroup consisting of a linear or branched alkyl , a substituted orunsubstituted aryl, and an alkylaryl. X is the same or different and isindependently selected from the group consisting of a halide, an alkyl,an alkylaryl having from 1 to about 10 carbon atoms, and a triflate.Suitable organometallic compounds include, for example, (C₅H₄CH₃)₂ZrCl₂,(C₅H₄CH₂C₆H₆)₂ZrF₂, (C₅H₄C₄H₉)₂ZrCl₂, and (C₅H₃CH₃C₂H₅)₂ZrBr₂.Preferably the organometallic compound is (C₅H₄C₄H₉)₂ZrCl₂. Combinationsof these organometal compounds can also be used.

The type and amount of the activator in the second catalyst compositionis the same as discussed previously for the first catalyst composition.Generally, the amount of the first organometal compound and the secondorganometal compound combined in the second catalyst composition is thesame as the amount of the first organometal in the first catalystcomposition. The ratio of the first organometal compound to the secondorganometal compound ranges from about 1:100 to about 100:1.

The second organometal compound can be contacted with the otheringredients of this catalyst by any method which was suitable for thefirst organometal compound. For example, it can be mixed with the firstorganometal compound in a hydrocarbon solution and pumped into thereactor separately. Or, the second organometal compound can be fed intoa precontacting vessel where all or some of the other ingredients may becontacted before being introduced into the reactor. Alternatively, allof the ingredients can be fed individually into the reactor directly.

Preferably, the activity of the second catalyst composition is similarto that for the first catalyst composition. In addition, aluminoxanes,fluoro-organo boron compounds, organochromium compounds, and MgCl₂ arenot required to produce the second catalyst composition, thereforeproviding the same benefits as previously discussed for the firstcatalyst composition.

The second catalyst composition can be used in the polymerizationprocesses as discussed previously for the first catalyst composition.When making bimodal polymers according to this third embodiment, it ispreferred to add comonomer and hydrogen in the polymerization reactionzone. Hydrogen can be used to control molecular weight, and comonomercan be used to control polymer density.

EXAMPLES

Preparation of (CpTiCl₂)₂O:

Under a dry nitrogen atmosphere, 600 mL of dry tetrahydrofuran (THF)were added to a flask containing 64.70 grams of cyclopentadienyltitanium trichloride obtained from the Strem Company to produce amixture. The mixture formed a first solution as the orange soliddissolved in the THF. Then, a second solution containing 200 mL of THFand 5.309 grams of water was added dropwise over a period of about 15minutes while the first solution was stirred vigorously to produce athird solution. The color of the third solution turned slightly morereddish. The third solution then was heated gently to 40° C. and allowedto stand at that temperature for several hours. After standing at roomtemperature for an additional 24 hours, the THF then was evaporatedunder vacuum leaving a yellow-brown solid of (CpTiCl₂)₂O.

Preparation of the Chlorided, Zinc-Containing Alumina:

A commercial alumina sold as Ketjen grade B alumina was obtained fromAkzo Nobel Chemical having a pore volume of about 1.78 cc/g and asurface area of about 350 m²/g. A solution of 435 mls of deionizedwater, 34.65 grams of zinc chloride, and 2.5 mls of nitric acid was madeand impregnated onto a 170.35 gram sample of Ketjen Grade B alumina toproduce a zinc-containing alumina. Thus, the zinc chloride loading was20% by weight of the alumina. The zinc-containing alumina then was driedovernight under vacuum at 100° C. and pushed through an 80 mesh screen.A portion of the zinc-containing alumina then was calcined in dry air at600° C. for three hours to convert the zinc species to a mixed zincoxide producing a calcined, zinc-containing alumina. Then, the calcined,zinc-containing alumina was activated in 25 gram batches as follows. 25grams of the calcined, zinc-containing alumina was heated under nitrogento 600° C. again and while still at 600° C., 2.4 mls of carbontetrachloride were injected into the gas stream where it evaporated andwas carried up through the fluidizing zinc-containing alumina bed toproduce a chlorided, zinc-containing alumina. The chlorided,zinc-containing alumina then was stored under dry nitrogen and latertested for polymerization activity.

Bench Scale Polymerization Runs:

Bench scale polymerizations runs were carried out in a one gallonstirred Autoclave Engineers reactor. It was first prepared for use bypurging with nitrogen and heating the empty reactor to 120° C. Aftercooling to below 40° C. and purging with isobutane vapors, a smallamount of the organometal compound, usually from 0.001 to 0.01 grams asindicated, was charged to the reactor under nitrogen. Then, anactivator, such as a MAO solution, was added, and the reactor wasclosed. Next, 1-hexene, if used, was injected into the reactor, followedby two liters of isobutane liquid added under pressure to produce areaction mixture. The reactor was subsequently heated to the desiredtemperature, usually 90° C., or as otherwise indicated. The reactionmixture was stirred at 700 revolutions per minute (rpm). In some runs,while heating, hydrogen was added to the reactor from one of twoauxiliary vessels of 55 cc (SV) or 325 cc (LV) volume. The amount ofhydrogen added was measured and expressed by the pressure drop on thisvessel as its contents were added the reactor. The final partialpressure of hydrogen on the reactor itself can be determinedapproximately by multiplying the measured pressure drop from theseauxiliary vessels by 0.163 (LV) or by 0.028 (SV). Ethylene then wasadded to the reactor and fed on demand to maintain a fixed totalpressure of 450 psig, or as otherwise indicated. The reactor wasmaintained at the specified temperature for about 60 minutes. Then, theisobutane and ethylene were vented from the reactor, and the reactorthen was opened. The polymer was collected usually as a dry powder. Insome cases, the polymer stuck to the reactor walls and had to be scrapedoff for recovery.

When a halided, metal-containing solid oxide component was used as theactivator, typically 0.25 grams of the halided, metal-containing solidoxide component was sealed in a glass tube to which a toluene solutioncontaining from 2 to 20 mg of the organometal compound were added aswell as 1 mL of a 1 molar heptane solution of the organoaluminum,usually triethylaluminum, to produce a pre-contacted catalyst mixture.The pre-contacted catalyst mixture then was added to the reactor undernitrogen.

Ethylene was polymerization grade ethylene obtained from Union CarbideCorporation. The ethylene was purified further through a column of ¼inch beads of Alcoa A201 alumina that had been activated at 250° C. innitrogen. Isobutane was polymerization grade obtained from PhillipsPetroleum Co., Borger, Tex. It was purified further by distillation, andit too was passed through a column of ¼ inch beads of Alcoa A201 aluminathat had been activated at 250° C. in nitrogen. The 1-hexene waspolymerization grade obtained from Chevron Chemicals. It was purifiedfurther by nitrogen purging and storage over 13× molecular sieves thathad been activated at 250° C. The methylaluminoxane (MAO) was obtainedfrom Albemarle Corporation as a 10% solution in toluene. Otherorganoaluminum compounds were obtained from Akzo Corporation as onemolar solutions in heptane.

Polymer Tests:

Bulk density was determined in lbs/ft as described in ASTM D1895-89, byweighing a 100 ml graduated cylinder in which polymer fluff had beenlightly tapped.

Polymer density was determined in grams per cubic centimeter (g/cc) on acompression molded sample, cooled at about 15° C. per hour andconditioned for about 40 hours at room temperature in accordance withASTM D1505-68 and ASTM D1928, procedure C.

Melt Index (MI) in grams of polymer per ten minutes was determined inaccordance with ASTM D1238, condition 190/2, at 190° C. with a 2,160gram weight. 190° C.

High load melt index (HLMI, g/10 min) was determined in accordance withASTM D1238, Condition 190/2.16, at 190° C. with a 21,600 gram weight.

Molecular weights and molecular weight distributions were obtained usinga Waters 150 CV gel permeation chromatograph (GPC) with trichlorobenzene(TCB) as the solvent, with a flow rate of 1 mL/minute at a temperatureof 140° C. BHT (2,6-di-tert-butyl-4-methylphenol) at a concentration of1.0 g/L was used as a stabilizer in the TCB. An injection volume of 220microliters were used with a nominal polymer concentration of 0.3 g/l(at room temperature). Dissolution of the sample in stabilized TCB wascarried out by heating at 160-170° C. for 20 hours with occasional,gentle agitation. The column was two Waters HT-6E columns (7.8×300 mm).The columns were calibrated with a broad linear polyethylene standard(Phillips Marlex® polyethylene BHB 5003) for which the molecular weighthad been determined.

Branch analysis was accomplished via solution 13C NMR spectra, whichwere collected from a deuterated trichlorobenzene solution of polymerusing either a GEQE200 NMR spectrometer at 75.5 MHZ, or a Varian 500 NMRspectrometer at 125.7 MHZ.

Examples 1-28

A number of bench-scale polymerization runs were made with (CpTiCl₂)₂Oand with a number of other related titanium based organometal compoundsfor comparison. The results of these tests are listed in Table 1.

In these runs, usually 0.25 g of the chlorided, zinc-containing aluminadescribed previously was charged to the reactor along with a fewmilligrams of the organometal compound, as indicated in the table, and asmall amount of the organoaluminum compound, usually 1 mL or 0.5 mL oftriisobutyl aluminum. In some cases, these ingredients were combined ina glass tube for a short time before being added to the reactor.

It can be seen from Table 1 that the inventive compound, designated as Ain the table, is considerably more active than any other compound thatwas tested. Comparative compounds included the closest relative to theinventive compound, the cyclopentadienyl titanium dichloride aryloxides,and also the precursor material, cyclopentadienyl titanium trichloride,and even the well-known “constrained geometry” catalyst from Dow.However, none of these compounds approached the activity exhibited fromthe inventive compound. Notice also that the inventive compound producedextremely high molecular weight polymer, which is desirable for abimodal combination of catalysts.

TABLE 1 Chlorided, Organometal Zinc- Organ- Compound Triiso- Chlorided,Containing ometal Ex- butyl- Zinc- Polymer Alumina Compound ample Temp.Hexene aluminum Containing Yield Time Activity Activity Density # TypeMg deg C. (g) (ml) Alumina (g) (g) (min) (gPE/g/h)* (gPE/g/h)* HLMI(g/cc) 1 A 6.0 80 25 0.5 0.250 339 30 2712 113,000 0.01 0.9289 2 A 6.080 25 0.5 0.250 331 30 2648 110,333 0.11 0.9280 3 A 6.0 80 90 0.5 0.250306 30 2448 102,000 0.06 0.9244 4 B 17.0 80 0 1 0.250 0 22 0 0 5 B 17.080 0 1 0.250 35 51 165 2,422 6 C 18.0 80 0 1 0.250 0 34 0 0 7 C 19.0 800 1 0.250 0 46 0 0 8 D 50.0 90 20 1 0.250 0 38 0 0 9 E 23.0 90 20 10.250 43 60 172 1,870 10 F 7.0 80 0 1 0.150 6 60 40 857 11 F 12.0 70 00.5 0.150 14 60 93 1,167 12 G 10.0 80 25 0.5 0.250 0 30 0 0 13 H 10.0 8025 0.5 0.250 89 30 356 8,900 14 I 10.0 80 25 0.5 0.250 5 30 20 500 15 J4.0 80 25 0.5 0.250 18 30 144 9000 16 J 4.0 80 25 0.5 0.250 20 30 16010,000 17 K 8.0 90 22 1 0.250 121 60 484 15,125 18 K 4.0 80 50 0.5 0.25045 30 360 22,500 0.05 0.9289 19 L 12.0 90 0 1 0.250 0 21 0 0 20 L 5.0 9011 1 0.249 40 30 161 8,000 21 L 10.0 90 20 1 0.250 13 60 52 1,300 22 L4.0 90 41 1 0.258 41 30 159 10,250 23 M 20.5 80 0 1 0.162 38 60 2351,854 24 M 17.4 80 5 1 0.158 33 60 209 1,897 25 M 9.7 80 10 1 0.147 5160 347 5,258 0 0.9309 26 N 6.0 80 25 0.5 0.250 90 30 360 15,000 27 O10.0 80 25 0.5 0.250 0 30 0 0 28 P 10.0 80 25 0.5 0.500 16 60 32 1600Code for Table 1 A is the inventive compound (CpTiCl₂)₂O where Cp =cyclopentadienyl. B is cyclopentadienyl titanium trichloride, orCpTiCl₃. C is pentamethylcyclopentadienyl titanium trichloride, or(CH₃)CpTiCl₃. D is pentamethylcyclopentadienyl titanium trimethoxide, or(CH₃)CpTi(OCH₃)₃ E is indenyl titanium trichloride, or IndTiCl₃. F isbis-cyclopentadienyl titanium dichloride, or Cp₂TiCl₂. G is1-methylindenyl titanium trichloride, or CH₃IndTiCl₃. H is1,2,3-trimethylindenyl titanium trichloride, or (CH₃)₃IndTiCl₃. I is1-phenylindenyl titanium trichloride, or C₆H₅IndTiCl₃. J iscyclopentadienyl titanium dichloride 2,5 di-t-butylphenoxide. K iscyclopentadienyl titanium dichloride 2,5 dimethylphenoxide. L ispentamethylcyclopentadienyl titanium dichloride 2,5diisopropylphenoxide. M is (t-butyl amido) (tetramethylcyclopentadienyl)dimethylsilane titanium dichloride, a constrained geometry catalyst ofDow Chemical Company. N is the cyclic tetramer (CpTiClO)₄. O iscyclopentadienyl titanium dichloride (p-ethoxyphenoxide). P iscyclopentadienyl titanium dichloride (p-methylphenoxide). ChloridedZinc-Containing Alumina Activity = grams of polyethylene per gram ofchlorided, zinc-containing alumina per hour Organometal CompoundActivity = grams of polyethylene per gram of organometal compound perhour

Examples 29-32

Bench scale polymerization runs were made at 80° C. with the inventiveorganometal compound A described previously and the chlorided,zinc-containing alumina. In each run, 1 mL of 1 molartriisobutylaluminum was added along with a varying amount of hexene. Thepolymers produced had a HLMI of zero. C-13 NMR branching analysis wasperformed on the polymers, and the following data in Table 2 wereobserved.

TABLE 2 Grams Ethyl Butyl Hexene Branches Branches Example No. AddedDensity (g/cc) Wt % Wt % 29-Inventive 10 0.9319 0.12 1.62 30-Inventive20 0.9300 0.10 3.18 31-Inventive 30 0.9280 0.10 4.62 32-Comparative 1000.9401 0 1.02

Butyl branching increased, as expected, with increased hexene. Theremarkable feature, however, is how much branching is incorporated withso little hexene added. This represents a high degree of comonomerincorporation efficiency. NMR detected ethyl branching as well, whichindicates in-situ butene generation. In Comparison Example 32, bis(n-butylcyclopentadienyl) zirconium dichloride, well known for its highactivity and for its ability to produce low molecular weight polymer,incorporated little hexene in comparison to the inventive compound A.

Thus, the first organometal compound and first catalyst composition ofthis invention: 1) displays high activity; 2) incorporates hexene well,and 3) also produces extremely high molecular weight polymer. This is aunique combination of characteristics that is ideal for producingbimodal polymers from a combination of organometal compounds withbranching concentrated in the high molecular weight part of thedistribution. The comparative compound in Table 2, bis(n-butylcyclopentadienyl) zirconium dichloride, makes an ideal companionto the inventive first catalyst composition because of its highactivity, yet poor incorporation efficiency, and its natural ability toproduce low molecular weight polymer. The two together form an excellentchoice for producing bimodal polymers.

Example 33

Bimodal Production Runs in Loop Reactor

Ethylene polymers were prepared also in a continuous particle formprocess (also known as a slurry process) by contacting a second catalystcomposition with ethylene and hexene comonomer. The medium andtemperature are thus selected such that the copolymer is produced assolid particles and is recovered in that form. Ethylene that had beendried over activated alumina was used as the monomer. Isobutane that hadbeen degassed by fractionation and dried over alumina was used as thediluent.

A liquid full 15.2 cm diameter pipe loop reactor having a volume of 23gallons (87 liters) was utilized. Liquid isobutane was used as thediluent, and occasionally some hydrogen was added to regulate themolecular weight of the polymer product. The reactor pressure was about4 Mpa (about 580 psi). The reactor temperature was set at 180° F. Thereactor was operated to have a residence time of 1.25 hours. The secondcatalyst composition was added through a 0.35 cc circulating ball-checkfeeder. At steady state conditions, the isobutane feed rate was about 46liters per hour, the ethylene feed rate was about 30 lbs/hr, and the1-hexene feed rate was varied to control the density of the polymerproduct. Ethylene concentration in the diluent was 14 mole percent.Catalyst concentrations in the reactor was such that the second catalystcomposition content ranges from 0.001 to about 1 weight percent based onthe weight of the reactor contents. Polymer was removed from the reactorat the rate of about 25 lbs per hour and recovered in a flash chamber. AVulcan dryer was used to dry the polymer under nitrogen at about 60-80°C.

The organoaluminum compound, triisobutylaluminum (TIBA), was obtainedfrom Akzo Corporation and was added as indicated in a concentration ofabout 1 to 250 parts per million by weight of the diluent. To preventstatic buildup in the reactor, a small amount (<5 ppm of diluent) of acommercial antistatic agent sold as Stadis® 450 usually was added.

Ethylene was polymerization grade ethylene obtained from Union CarbideCorporation. This ethylene was purified further through a column of ¼inch beads of Alcoa A201 alumina which had been activated at 250° C. innitrogen. Isobutane was polymerization grade obtained from PhillipsPetroleum Co., Borger, Tex. It was purified further by distillation andit too was passed through a column of ¼ inch beads of Alcoa A201 aluminathat had been activated at 250° C. in nitrogen. The 1-hexene waspolymerization grade obtained from Chevron Chemicals. It was purifiedfurther by nitrogen purging and storage over 13× molecular sieves thathad been activated at 250° C.

Several bimodal polymers then were made in the continuous loop reactorby co-feeding two organometal compounds simultaneously. The samechlorided, zinc-containing alumina as described previously was used asthe activator, along with 250 ppm by weight of triisobutyl aluminum.Hexene was pumped into the reactor at the rate of 12.5 lbs per hour. Thehexene to ethylene feed weight ratio was 0.33. Reactor temperature was180° F. Density of the polymer was maintained at 0.920 g/cc, and thebulk density was about 22 lbs/cubic foot. The two organometal compoundsused were the inventive compound described previously, (CpTiCl₂)₂O,which produces the high molecular weight copolymer, andbis(n-butylcyclopentadienyl) zirconium dichloride also describedpreviously in Table 2, which produces the low molecular weight lessbranched polymer.

The relative amounts of the two organometal compounds were varied toproduce five different polymers of varying breadth of molecular weightdistribution. The GPC traces of the five polymers are shown in FIG. 1.Notice that as the inventive compound, (CpTiCl₂)₂O, is increased inamount relative to the bis(n-butylcyclopentadienyl) zirconiumdichloride, the polymer molecular weight distribution broadens. Thepolydispersity (weight average molecular weight divided by numberaverage molecular weight) produced by the (CpTiCl₂)₂O alone was about 9,while the polydispersity of the bis(n-butylcyclopentadienyl) zirconiumdichloride alone was about 2.3. However, by combining the twoorganometal compounds, polydispersities of 12-17 was obtained,signifying greater breadth of molecular weight distribution.

While this invention has been described in detail for the purpose ofillustration, it is not intended to be limited thereby but is intendedto cover all changes and modifications within the spirit and scopethereof.

1. A process to produce a catalyst composition, said process comprising contacting at least one first organometal compound, at least one second organometal compound, and at least one activator; wherein said first organometal compound is represented by the formula: (C₅R₅)TiX₂—O—(C₅R₅)TiX₂ wherein R is the same or different and is independently selected from the group consisting of hydrogen and a hydrocarbyl group having from 1 to about 10 carbon atoms; wherein said hydrocarbyl group is a linear or branched alkyl, a substituted or unsubstituted aryl, or an alkylaryl; wherein X is the same or different and is independently a halide, an alkyl, an aklylaryl having from 1 to about 10 carbon atoms, or a triflate; wherein said second organometal compound is represented by the formula (C₅R₅)₂ZrX₂; wherein said R of the second organometal compound is the same or different and is independently selected from hydrogen or a hydrocarbyl group having from 1 to about 10 carbon atoms; wherein said hydrocarbyl group is a linear or branched alkyl, a substituted or unsubstituted aryl, or an alkylaryl; wherein X is the same or different and is independently a halide, an alkyl, an aklylaryl having from 1 to about 10 carbon atoms, or a triflate; and wherein said activator is selected from aluminoxanes, fluoro-organic borate compounds, or treated solid oxide components in combination with at least one organoaluminum compound.
 2. A process according to claim 1 wherein said aluminoxanes are prepared from trimethylaluminum or triethylaluminum.
 3. A process according to claim 2 wherein said aluminoxane is used in combination with a trialkylaluminum.
 4. A process according to claim 1 wherein the molar ratio of the aluminum in said aluminoxane to the transition metal in said first organometal compound is in a range of about 1:1 to about 100,000:1.
 5. A process according to claim 4 wherein the molar ratio of the aluminum in said aluminoxane to the transition metal in said first organometal compound is in a range of 5:1 to 15,000:1.
 6. A process according to claim 1 wherein said fluoro-organo borate compounds are selected from N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, lithium tetrakis(pentafluorophenyl)borate, tris(pentafluorophenyl)boron, N,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, or triphenylcarbenium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, or mixtures thereof.
 7. A process according to claim 6 wherein the amount of said fluoro-organo borate compound is in a range of from about 0.5 mole to about 10 moles of fluoro-organo borate compound per mole of said first organometal compound.
 8. A process according to claim 7 wherein the amount of said fluoro-organo borate compound is in a range of from 0.8 mole to 5 moles of said fluoro-organo borate compound per mole of said first organometal compound.
 9. A process according to claim 1 wherein said treated solid oxide component is a halided solid oxide component or a halided, metal-containing solid oxide component; wherein said halided solid oxide component comprises a halogen and a solid oxide component; wherein said halided, metal-containing solid oxide component comprises a halogen, a metal, and a solid oxide component; wherein said solid oxide component is selected from alumina, silica-alumina, aluminophosphate, aluminoborate, or a mixture of any two or more of said solid oxide components; wherein said metal is selected from zinc, nickel, vanadium, copper, silver, gallium, tungsten, molybdenum, or tin; and wherein said halogen is chlorine or bromine.
 10. A process according to claim 9 wherein said organoaluminum compound is selected from triisobutylaluminum, diethylaluminum hydride, dipentylalumium ethoxide, dipropylaluminum phenoxide, or mixtures thereof.
 11. A process according to claim 9 wherein said organoaluminum compound is triisobutylaluminum or triethylaluminum.
 12. A process according to claim 9 wherein said solid oxide component has a pore volume greater than about 0.8 cc/g.
 13. A process according to claim 9 wherein said solid oxide component has a surface area in a range of about 200 to about 800 m²/g.
 14. A process according to claim 9 wherein said solid oxide compound is alumina.
 15. A process according to claim 9 wherein said halogen is chlorine.
 16. A process according to claim 9 wherein said metal is zinc.
 17. A process to produce a first catalyst composition comprising contacting bis(cyclopentadienyl titanium dichloride)oxide, a chlorided, zinc-containing alumina, and an organoaluminum compound which is triisobutylaluminum or triethylaluminum to produce said first catalyst composition; wherein the amount of zinc present is in a range of about 0.5 millimoles to about 5 millimoles of zinc per gram of alumina.
 18. A process according to claim 1 wherein said second organometal compound is bis(n-butylcyclopentadienyl)zirconium dichloride.
 19. A process to produce a second catalyst composition, said process comprising contacting bis(cyclopentadienyl titanium dichloride)oxide, bis(n-butylcyclopentadienyl)zirconium dichloride, a chlorided, zinc-containing alumina, and triisobutylaluminum.
 20. A catalyst composition produced by the process of claim
 1. 21. A catalyst composition produced by the process of claim
 19. 22. A catalyst composition according to claim 19 wherein said catalyst composition has an activity greater than 1000 grams of polymer per gram of activator per hour under slurry polymerization conditions, using isobutane as a diluent, with a polymerization temperature of 90° C., and an ethylene pressure 550 psig.
 23. A catalyst composition according to claim 19 wherein said catalyst composition has an activity greater than 2000 grams of polymer per gram of activator per hour under slurry polymerization conditions, using isobutane as a diluent, with a polymerization temperature of 90° C., and an ethylene pressure of 550 psig.
 24. A catalyst composition according to claim 19 wherein a weight ratio of said organoaluminum compound to said treated solid oxide component in said catalyst composition ranges from about 3:1 to about 1:100.
 25. A catalyst composition according to claim 24 wherein said weight ratio of said organoaluminum compound to said treated solid oxide component in said catalyst composition ranges from 1:1 to 1:50.
 26. A catalyst composition according to claim 19 wherein a weight ratio of said treated solid oxide component to said organometal compound in said catalyst composition ranges from about 1000:1 to about 10:1.
 27. A catalyst composition according to claim 26 wherein said weight ratio of said treated solid oxide component to said organometal compound in said catalyst composition ranges from 250:1 to 20:1.
 28. A catalyst composition according to claim 20 wherein said catalyst composition has an activity greater than 1000 grams of polymer per gram of activator per hour under slurry polymerization conditions, using isobutane as a diluent, with a polymerization temperature of 90° C., and an ethylene pressure 550 psig.
 29. A catalyst composition according to claim 20 wherein said catalyst composition has an activity greater than 2000 grams of polymer per gram of activator per hour under slurry polymerization conditions, using isobutane as a diluent, with a polymerization temperature of 90° C., and an ethylene pressure of 550 psig.
 30. A catalyst composition according to claim 20 wherein a weight ratio of said organoaluminum compound to said treated solid oxide component in said catalyst composition ranges from about 3:1 to about 1:100.
 31. A catalyst composition according to claim 20 wherein said weight ratio of said organoaluminum compound to said treated solid oxide component in said catalyst composition ranges from 1:1 to 1:50.
 32. A catalyst composition according to claim 19 wherein a weight ratio of said treated solid oxide component to said first and second organometal compounds in said catalyst composition ranges from about 1000:1 to about 10:1.
 33. A catalyst composition according to claim 19 wherein a weight ratio of said treated solid oxide component to said first and second organometal compounds in said catalyst composition ranges from 250:1 to 20:1.
 34. A polymerization process comprising contacting at least one monomer and said catalyst composition of claim 19 under polymerization conditions to produce a polymer.
 35. A process according to claim 34 wherein said polymerization conditions comprise slurry polymerization conditions.
 36. A process according to claim 35 wherein said contacting is conducted in a loop reaction zone.
 37. A process according to claim 36 wherein said contacting is conducted in the presence of a diluent that comprises, in major part, isobutane.
 38. A process according to claim 34 wherein at least one monomer is ethylene.
 39. A process according to claim 38 wherein at least one monomer comprises ethylene and an aliphatic 1-olefin having 3 to 20 carbon atoms per molecule.
 40. A polymerization process comprising contacting at least one monomer and said catalyst composition of claim 20 under polymerization conditions to produce a bimodal polymer.
 41. A process according to claim 40 wherein said polymerization conditions comprise slurry polymerization conditions.
 42. A process according to claim 41 wherein said contacting is conducted in a loop reaction zone.
 43. A process according to claim 42 wherein said contacting is conducted in the presence of a diluent that comprises, in major part, isobutane.
 44. A process according to claim 40 wherein at least one monomer in ethylene.
 45. A process according to claim 44 wherein at least one monomer comprises ethylene and an aliphatic 1-olefin having 3 to 20 carbon atoms per molecule.
 46. A process to produce a catalyst composition, said process comprising contacting at least one first organometal compound, at least one second organometal compound, and at least one activator; wherein said first organometal compound is represented by the formula; (C₅R₅)TiX₂—O—(C₅R₅)TiX₂ wherein R is the same or different and is independently selected from the group consisting of hydrogen and a hydrocarbyl group having from 1 to about 10 carbon atoms; wherein said hydrocarbyl group is a liner or branched alkyl, a substituted or unsubstituted aryl or an alkylaryl; and wherein X is the same or different and is independently a halide, an alkyl, an aklylaryl having from 1 to about 10 carbon atoms or a triflate; wherein said second organometal compound is represented by the formula (C₅R₅)₂ZrX₂; wherein said R of said second organometal compound is the same or different and is independently a hydrogen or a hydrocarbyl coup having from 1 to about 10 carbon atoms; wherein said hydrocarbyl group is a linear or branched alkyl, a substituted or unsubstituted aryl, or an alkylaryl; and wherein X can be the same or different and is independently a halide, an alkyl, an alkylaryl having from 1 to about 10 carbon atoms, or a triflate, wherein said activator is at least one treated solid oxide component in combination with at least one organoaluminum compound; and wherein there is a substantial absence of aluminoxanes and fluoro-organo boron compounds.
 47. A process according to claim 46 wherein said first organometal compound is [(C₅H₄CH₃)TiCl₂]₂O, [(C₅H₄CH₂C₆H₅)TiF₂]₂O, [(C₅H₃CH₃C₂H₅)TiBr₂]₂O, or [(C₅H₅)TiCl₂]₂O.
 48. A process according to claim 47 wherein said first organometal compound is [(C₅H₅)TiCl₂]₂O.
 49. A process according to claim 46 wherein said treated solid oxide component is a halided solid oxide component or a halided, metal-containing solid oxide component; wherein said halided solid oxide component comprises a halogen and a solid oxide component; wherein said halided, metal-containing solid oxide component comprises a halogen, a metal, and a solid oxide component; wherein said solid oxide component is alumina, silica-alumina, aluminophosphate, aluminoborate, or a mixture of any two or more of said solid oxide components; wherein said metal is zinc, nickel, vanadium, copper, silver, gallium, tungsten. molybdenum, or tin; and wherein said halogen is chlorine or bromine.
 50. A process according to claim 49 wherein said organoaluminum compound is triisobutylaluminum, diethylaluminum hydride, dipentylalumium ethoxide, dipropylaluminum phenoxide, or a mixture of any two or more of said organoaluminum compounds.
 51. A process according to claim 50 wherein said organoaluminum compound is triisobutylaluminum or triethylaluminum.
 52. A process according to claim 46 wherein said solid oxide component has a pore volume greater than about 0.8 cc/g.
 53. A process according to claim 46 wherein said solid oxide component has a surface area in a range of about 200 to about 800 m²/g.
 54. A process according to claim 46 wherein said solid oxide component is alumina.
 55. A process according to claim 49 wherein said halogen is chlorine.
 56. A process according to claim 49 wherein said metal is zinc.
 57. A process according to claim 46 wherein said second organometal compound is bis(n-butylcyclopentadienyl)zirconium dichloride.
 58. A process according to claim 46 wherein the catalyst composition has an activity greater than 1000 grams of polymer per gram of activator per hour under slurry polymerization conditions, using isobutane as a diluent, with a polymerization temperature of 90° C., and an ethylene pressure of 550 psig.
 59. A process according to claim 58 wherein the catalyst composition has an activity greater than 2000 grams of polymer per gram of activator per hour under slurry polymerization conditions, using isobutane as a diluent, with a polymerization temperature of 90° C., and an ethylene pressure of 550 psig.
 60. A process according to claim 46 wherein a weight ratio of said organoaluminum compound to said treated solid oxide component in the catalyst composition thus-produced ranges from about 3:1 to about 1:100.
 61. A process according to claim 60 wherein said weight ratio of said organoaluminum compound to said treated solid oxide component in said catalyst composition ranges from 1:1 to 1:50.
 62. A process according to claim 46 wherein a weight ratio of said treated solid oxide component to said first and second organometal compounds in said catalyst composition ranges from about 1000:1 to about 10:1.
 63. A process according to claim 62 wherein said weight ratio of said treated solid oxide component to said first and second organometal compounds in said catalyst composition ranges from 250:1 to 20:1. 